how am i supposed to do the self employed deductions over multiple unpID YEArs? what do i need to know

Each tax year is separate and must be prepared using the software and forms for the specific tax year in which the income was received.  You cannot combine them in any way.   You are required to file a tax return for any year in which you earned even $400 of self-employment income.  

You might want to google and look for cheaper software than TurboTax to see if you can find a way to prepare those returns.

TurboTax has software for 2021 onward.   Software is no longer available from TurboTax for earlier years, nor would it be supported even if you find it on eBay, etc.  Updates are not available.   It is also too late to receive a tax refund for a tax year earlier than 2021---those refunds have been forfeited.   BUT if you owe tax due you still have to pay with penalties and interest.   There might be other software providers that have software for those years, but you will not receive refunds for the returns even if the forms show a refund.

You cannot change the tax year.   The current online program is for 2024 only.   Only a 2024 return can be prepared online and only a 2024 return can be e-filed.

Online preparation and e-filing for 2021, 2022, and  2023 is permanently closed.

Note:  The desktop software you need to prepare the prior year return must be installed/downloaded to a full PC or Mac.  It cannot be used on a mobile device.

To file a return for a prior tax year

 If you need to prepare a return for 2021, 2022, or 2023  you can purchase and download desktop software to do it, then print, sign,  and mail the return(s)

https://turbotax.intuit.com/personal-taxes/past-years-products/

You may also want to explore purchasing the software from various retailers such as Amazon, Costco, Best Buy, Walmart, Sam’s, etc.

Remember to prepare your state return as well—if you live in a state that has a state income tax.

https://ttlc.intuit.com/turbotax-support/en-us/help-article/state-taxes/contact-state-department-revenue/L9qVToi02_US_en_US?uid=m6e06um0

When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s.  Use a mailing service that will track it, such as certified mail so you will know the IRS/state received the return.

Federal and state returns must be in separate envelopes and they are mailed to different addresses.  Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.

What do you mean by unpaid previous years?  You didn't file and pay your taxes. 

If you did not file your taxes from previous years, you will need to download the previous year tax programs as they are not available online.  Then you would enter your income and expenses for the appropriate year.  You cannot combine years.  

If your car was stolen in 2023, when you file you would report it as "sold" for whatever the insurance company paid you.  Any depreciation you claimed in previous years would be added back.  Your deduction or loss would then be allocated between business and personal use.  So if the vehicle was 10% business and 90% personal, then your loss would only be 10% of the actual loss.  The personal portion of the loss is not deductible. 

Also, if you are expecting a refund, you cannot claim a refund for 2021 or earlier as the 3 years have passed.  If you did NOT file, you should still file.  Payments due when you do not file last forever and collect interest and penalties.